Apologizing to a deceased victim

Hi,

If one harmed another person, and then his victim passed away, then he should go to the victim's grave, bringing a minyan with him, and say, "I have sinned to HaShem, Gd of Israel, and to this person, to whom I did ...."

He should also refund any monetary debt to the victim's heirs. If the heirs are unknown, he should leave the money with the local court.

(Rambam, Mishneh Torah, Laws of Repentance 2:11)

Have a great day,
Mordechai